The new unitized masonry structure described in this specification is a construction system that is designed to easily and quickly install in any location without the need for mortar, water, or power. In the United States alone there are over 4000 block manufacturing companies. Traditionally, building blocks and bricks are attached to each other by either of two methods. The first is by gravity, which includes stacking, arches, and flying buttresses. The second is by mortar and mortar equivalent methods, such as various types of mortar, epoxy, or blocks having their cores filled with concrete, with or without reinforcing steel bars (rebars). This attachment usually includes mortar with reinforcing wire in the joints and also includes attachment between masonry units with concrete and rebars in such shapes as bond beam blocks and pier blocks.
When reinforcement means have been used with block, it is typically accomplished with either long rebars or long steel rods or stranded cables placed in the cavities called ducts. The usual reinforcement is without any tensioning of the steel reinforcement, either pre-tensioning or post tensioning. Pre and post tensioning, as one well skilled in the art of construction engineering and techniques knows, increases the overall strength of the concrete unit. Until recently, post tensioning has only been used with a complete stack of block in conjunction with the placement of mortar between each layer. Up to now, most specialty block systems with rods and plates have required very complex design and high levels of skill by construction designers and engineers.
In the latter months of 2005, a newer technique of a bolt, block and bar system—called Bolt-A-Blok—introduced a basic unitized post tensioning where a loose bar is utilized as an anchor across the hollow cavity (or duct) of a concrete masonry unit (CMU) or block. The bar (anchor) has apertures with and without threads which are then individually connected by a through bolt which is essentially the tendon. The bolt (tendon) and bar (anchor) network required some care in the placement of the bar to assure uniformity of the reinforcement web of the tendons and anchors. The improved method and system described in this new system called a UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES has been devised that essentially “locates” the bars uniformly in a recessed cavity or in a pocket of the concrete masonry unit (CMU). Another embodiment of the new system eliminates bar placement entirely by embedding the bars into the CMU during the manufacturing of the block. These new configurations eliminate any gap between the adjacent CMUs. No filling or caulking of the space is required. Various other embodiments and improvements are described which greatly enhance the post tensioning system first introduced under the Bolt-A-Blok system established as prior art.
A. Introduction of the Problems Addressed
Since most masonry structures use mortar, several things are required. First, the mortar requires water. Second, in most cases, the laying of block requires a skilled block or brick mason. Third, a means of power to mix the mortar is normal. Fourth, elaborate bracing and reinforcement is needed until the mortar cures and reaches its strength. During this curing time the overall structure is “fragile” to wind, severe temperatures, and other natural weather and environmental conditions. During curing, occupation and use of the structure is unwise. Scaffolding often remains in place awaiting some cure before additional blocks are added to the height of the structure. If proper preparation and care are not provided to reduce the environmental impacts, the mortar and overall structure may result in cracking and diminished structural strength.
Reinforcing means 51 are often provided to improve strength (as shown in FIG. 4D), but the need to have bracing and other protection in place for many days and even weeks is still needed. Traditional masonry structures which use mortar often have straight sections 50 which are staggered and have wire mesh and an occasional rebar (as shown in FIG. 4 C).
Finally, once built, the traditional masonry systems become a fixed structure. Unless very special and complex features provisions are added to the normal block, rebar and mortar system, the structure is essentially not re-useable and must be “demolished” to be removed.
These stated requirements each limit the use of the traditional masonry with mortar system. The new system called Bolt-A-Blok facilitated a clear improvement to traditional construction systems and their limitations. The Bolt-A-Blok system does not require special skills to construct; does not need water and power; does not require elaborate bracing; provides immediate occupancy or use; needs no curing time; and, is re-useable if desired since it is not destroyed when disassembled and moved. Bolt-A-Blok system was an improvement to decrease the time to build or rebuild areas with minimal skilled labor. The Bolt-A-Blok system provides a far superior and more consistent strength structure than the traditional mortar constructed structure.
While the Bolt-A-Blok system addressed many of the common requirements and limitations to traditional mortar and block construction methods, the system has some room for improvement. These improvements are addressed by the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES described below. The improvements over Bolt-A-Blok include:                a. elimination of any gap between the CMUs. No filling or caulking of the space is required.        b. precise placement of the anchor bar.        c. faster build time with the recessed channels or the embedded bars.        d. commercial tracking of the invention with the embedded bars.        e. stronger military/defense use and anti-blast applications.        f. features for easier, faster build with placement aids.        g. features with anti-turn and quick connections with oval plates/washers and threaded tendons.        
B. Prior Art
Historically, few patented devices have attempted to address the problem as stated. The building industry has made little progress for a unitized, post tension system. Even so, blocks have required very special and often complex configurations to even handle rods and plates and then the have taught only limit rods in special blocks. One such device is described in U.S. Pat. No. 5,511,902 (1996) issued to Center which teaches an Instant levy block system. This is a complex, specially made block for constructing a levy, comprising a plurality of blocks, a plurality of connecting pegs, and a plurality of stakes. Each part is uniquely designed and made whereas the new UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES as described here utilizes a uniform, readily available block design for a concrete masonry unit (CMU).
Another block device is described in A U.S. Pat. No. 5,809,732 which was issued to Farmer, Sr. et al (1998) which teaches a masonry block with an embedded plate. The concrete masonry block has an external plate or plates that are anchored through the concrete masonry block. The external plates are cast into the concrete masonry block in the mold during casting. These plates and metal pieces are not taught as being part of a post tensioning system now shown cast within the hollow cavities as addressed by the new UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES.
Another device for construction is taught by U.S. Pat. No. 6,098,357 issued to Franklin et al. (2000). This art discloses a modular pre-cast construction block system with a wall subsystem and a foundation subsystem. The wall subsystem has a number of wall units having cavities and pre-stressed tension cables are cast therein the cavity. This teaches precast walls and pass through cable which are specially made, require water, and are not readily re-useable like the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES. Also, the tensioning system is not unitized or placed throughout the entire structure.
A somewhat re-useable system 49 is taught in the U.S. Pat. No. 6,178,714 issued to Carney, Jr. (2001) (as shown in FIGS. 4A and 4B). The long rods go through apertures in the specially cast block and the precast structures. No description of pre or post tensioning is taught or claimed. The configuration of special length rods, special blocks, special plates and a complex system that requires powered equipment to construct is unlike the simple components of the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES.
A Mortar less wall structure is taught in U.S. Pat. No. 6,691,471 issued to Price (2004). Here a wall structure comprising of columns of preformed, lightweight, stacked blocks, with the columns of blocks connected to each other by elongated, vertically oriented, support beams. Preferably, the wall structure is operatively connected to a structure by one or more brackets. The beams and blocks are special configuration, not readily available and with limited uses.
A pre-cast, modular spar system having a cylindrical open-ended spar 55 of relatively uniform cross section is taught in a U.S. Pat. No. 6,244,785 issued to Richter, et al (2001) (as shown in FIG. 5 B). The spar sections are formed by joining arcuate segments and stacking the sections. No design is shown that anticipates this UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES.
An interlocking, mortar less system is accomplished by some other devices. However, none of them are found to show a structural unitized post tensioning system as described for the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES in the materials below. An example of one such interlocking device 56 is taught by U.S. Pat. No. 4,640,071 issued to Haener (1987). This is shown as FIG. 5 C and teaches a block of concrete or the like for use in constructing a mortar less wall. The device provided includes a spaced parallel pair of upright sidewalls having flat bottoms and tops and bearing integral block interlocking connectors and various configurations on their opposite ends. The sidewalls are integrally connected by means of these configurations. This is not the configuration taught by the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES. Likewise, no post tensioning is taught to increase the structural integrity and strength.
The Bolt-A-Block system was filed Nov. 10, 2005 by Roger Marsh et al with Ser. No. 11/271,703. This basic mortar less system taught a masonry structure comprising a plurality of regular masonry blocks and/or bricks connected to each other by a plurality of metal bars and a plurality of standard metal threaded fasteners thereby forming a post tensioned structure. This Bolt-A-Block system is generally shown in FIG. 3. Preferably, the blocks are operatively connected to each other as a structure by simple mechanical tools. Each interconnection results in a unitized post tensioned member that, when interconnected to the adjacent members, forms a comparatively higher strength structure than systems made of mortar and reinforced mortar. The method used to create this structure is a simple, waterless, mortar less interconnection process that is completed by a series of simple individual steps of fastening the blocks and bars into a strong and durable structure. Once connected the structure is strong and durable. Important to note is that a small gap 44A occurs between the adjacent blocks 30 due to the placement of the bars 33. This separation is then filled or caulked to complete the wall surface. If desired, the structure may be disassembled and the components be re-used. This new UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES provides significant improvement and changes to the Bolt-A-Blok system that are not anticipated by the Bolt-A-Blok system. The improvements locate the bar (anchors) and increase the speed of build for the mortar less system. The recessed and embedded features remove the gap and need no filling. In addition, several embodiments provide higher strength options that increase the use for defense and anti-terrorism applications.
Traditional post-tensioned units 52 may have various configurations (as shown in FIG. 4E). To date this technology has been essentially unobvious as being applied at a unitized configuration. Individual blocks are attached to each other and now, as a new combination, perform as if it were all one post-tensioned beam, bridge, wall, or structure. This UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES works equally well with all sizes of concrete masonry units.
Traditional Post-Tensioned reinforcing consists of very high strength steel strands or bars. Typically, strands are used in horizontal applications like foundations, slabs, beams, and bridges; and bars are used in vertical applications like walls and columns. A typical steel strand used for post-tensioning has a tensile strength of 270,000 pounds per square inch. This actually teaches against the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES use of individual, standard bolts and simple fasteners. Post-tensioning using plates, or bars, between the masonry units is a totally new way of combining steel and concrete and is sound engineering practice.
None of the prior art teaches all the features and capabilities of the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES. As far as known, there are no systems at the present time which fully meet the need for a unitized, post-tensioned masonry block structure as well as the UNITIZED POST TENSION BLOCK SYSTEM FOR MASONRY STRUCTURES. It is believed that this system is made with component parts, is built with simple tools, needs no mortar, provides a much stronger structure than mortar structures, and is ready for immediate use and occupation upon construction.